i have read a few of these DIY tank builds and i don't understand y people seal the wood with some kind of rubber epoxy stuff. they are always having leak issues and and redoing a wall or something. why dont u just put down a thin sheet of glass on the plywood and seal it that way. then when the viewing window goes into place u can use silicon on the floor because the floor will be plywood topped with a 1/8" sheet of glass same with the sides and back all screw holes will be covered and sealed as well with these sheets of glass, even all the seems can be sealed with the proven and tested silicon. if every thing is braced properly then there should be little to no flexing. i want to do a tank build some day and this is what i was thinking i would do is there a reason that people don't do this or is it just a new idea???